Text::ParseWords - parse text into an array of tokens or array of arrays
use Text::ParseWords; @lists = &nested_quotewords($delim, $keep, @lines); @words = "ewords($delim, $keep, @lines); @words = &shellwords(@lines); @words = &parse_line($delim, $keep, $line); @words = &old_shellwords(@lines); # DEPRECATED!
The &nested_quotewords() and "ewords() functions accept a delimiter (which can be a regular expression) and a list of lines and then breaks those lines up into a list of words ignoring delimiters that appear inside quotes. "ewords() returns all of the tokens in a single long list, while &nested_quotewords() returns a list of token lists corresponding to the elements of @lines. &parse_line() does tokenizing on a single string. The &*quotewords() functions simply call &parse_lines(), so if you're only splitting one line you can call &parse_lines() directly and save a function call.
The $keep
argument is a boolean flag. If true, then the tokens are split on the specified delimiter, but all other characters (quotes, backslashes, etc.) are kept in the tokens. If $keep
is false then the &*quotewords() functions remove all quotes and backslashes that are not themselves backslash-escaped or inside of single quotes (i.e., "ewords() tries to interpret these characters just like the Bourne shell).
NB: these semantics are significantly different from the original version of this module shipped with Perl 5.000 through 5.004. As an additional feature, $keep
may be the keyword ``delimiters'' which causes the functions to preserve the delimiters in each string as tokens in the token lists, in addition to preserving quote and backslash characters.
&shellwords() is written as a special case of "ewords(), and it does token parsing with whitespace as a delimiter-- similar to most Unix shells.
The sample program:
use Text::ParseWords; @words = "ewords('\s+', 0, q{this is "a test" of\ quotewords \"for you}); $i = 0; foreach (@words) { print "$i: <$_>\n"; $i++; }
produces:
0: <this> 1: <is> 2: <a test> 3: <of quotewords> 4: <"for> 5: <you>
demonstrating:
Replacing "ewords('\s+', 0, q{this is...})
with &shellwords(q{this is...})
is a simpler way to accomplish the same thing.
Maintainer is Hal Pomeranz <pomeranz@netcom.com>, 1994-1997 (Original author unknown). Much of the code for &parse_line() (including the primary regexp) from Joerk Behrends <jbehrends@multimediaproduzenten.de>
Examples section another documentation provided by John Heidemann <johnh@ISI.EDU>
Bug reports, patches, and nagging provided by lots of folks-- thanks everybody! Special thanks to Michael Schwern <schwern@envirolink.org> for assuring me that a &nested_quotewords() would be useful, and to Jeff Friedl <jfriedl@yahoo-inc.com> for telling me not to worry about error-checking (sort of-- you had to be there).
If rather than formatting bugs, you encounter substantive content errors in these documents, such as mistakes in the explanations or code, please use the perlbug utility included with the Perl distribution.